Silacylcobutanes, methods for the preparation thereof, and polymers containing silacyclobutane units are known in the art. For example, U.S. Pat. No. 4,985,565 to Baney et al. discloses a silacyclobutane having the formula: ##STR2## where R' is a monovalent substituted or unsubstituted hydrocarbon group or Y, R" and R'" are independently hydrogen or a monovalent substituted or unsubstituted hydrocarbon group, Y is a monovalent group having a nitrogen or oxygen atom bonded to the silicon atom of the silacyclobutane, and x is from 0 to 3.
U.S. Pat. No. 5,001,187 to Liles et al. discloses an aqueous silicone emulsion of polydiorganosiloxane having silacyclobutane groups, comprising the product obtained by the emulsion polymerization of a polydiorganosiloxane oligomer having the formula HO(R.sup.a.sub.2 SiO).sub.m H and a silacyclobutane having the formula: ##STR3## wherein Y is a group or atom reactive with the SiOH group of the oligomer; R.sup.a is a monovalent hydrocarbon or substituted hydrocarbon group having 1 to 6 carbon atoms; R.sup.b and R.sup.c are hydrogen, hydrocarbon groups, or substituted hydrocarbon groups; and m is from 3 to 500.
Auner et al. disclose the synthesis of silicon dichloro substituted 3-vinyl-1-silacyclobutanes by reaction of equimolar amounts of trichlorovinylsilane and tert-butyllithium and an excess of a 1,3-butadiene (Organometallics 1993, 12(10), 4123-4134).
UK Patent Application GB 2326417 to Auner et al. discloses silacyclobutane compounds, silacyclobutene compounds, and siloxane polymers containing silacyclobutane and/or silacyclobutene units. The silacyclobutane compounds have the formula: ##STR4## wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4, and R.sup.5 are independently a hydrocarbon group or hydrogen; R.sup.6 is alkyl having at least 4 carbon atoms, X is a hydrolyzable group, and R.sup.8 is R.sup.1 or X. Examples of X include halogen and hydrocarbonoxy. The UK patent application teaches that R.sup.1 and R.sup.4 are preferably methyl groups or vinyl groups. The UK patent application also teaches that the siloxane polymers have improved resistance to low temperatures.
Although the above-cited references disclose various silacyclobutane compounds, none of the references teach the silacyclobutane compounds of the present invention having a substituted or unsubstituted ethynyl group attached to the ring C-3 position, the method of preparing the silacyclobutane compounds, the silane polymers, or the siloxane polymers of the present invention.